Microfluidics is experiencing explosive growth in new product developments. Already there are many commercial applications for electro microfluidic devices such as chemical sensors, biological sensors, and drop ejectors for both printing and chemical analysis. The number of micromachined microfluidic devices is expected to increase dramatically in the near future. Manufacturing efficiency and integration of microfluidics with electronics will become important. In order to realize applications for these devices, an efficient method for packaging microfluidic devices is needed.
The biggest stumbling block to commercial success is the lack of general, simple and effective packaging techniques. Packaging of a miniaturized chemical analysis system, also known as a “lab-on-a-chip,” is a very important element and plays several roles. Microfluidic packaging has to protect the sensitive functional unit from environmental factors that could affect its performance, like moisture, high temperature, vibration or corrosion. It also has to provide the component's connection to the outside world through electrical, optical and other types of interfaces. Not only should packaging not hinder function in any way, it should be a value-added asset. For example, a microfluidic sensor package would add this value if it contained a tiny pipeline to bring the media to be measured to the device reliably and efficiently. Other concepts have the package forming part of the sensing structure itself, becoming part of the device's own complex system instead of just a non-functional casing around it.
It is highly desirable that the MEMS (microelectromechanical systems) industry define a standard package for each application category. If a reasonable standard regarding inputs and outputs is available, then one microfluidic package can be appropriate for several different devices.
The present invention could serve as a standardization model for the microfluidics industry. Injection molded microfluidic packages with channels for fluid flow, input and output ports are integrally formed in the molded package. Shapes and sizes of the output ports are standardized and designed to interlock; thus, permitting the interconnection of microfluidic packages in an extended series. For packages that must pipe gases or liquids around on a chip, it will save on resources; it will mean that the entire sensor mechanism does not need to be replaced, just selected modules.
Microfluidic devices and networks in the prior art include, those containing multiple layers as reported in U.S. Pat. No. 6,645,432 to Anderson et al., and sealed by aligning two surfaces and removing a liquid to cause the seal. U.S. Pat. No. 6,615,857 to Sinha, et al. describes linearly arranged flow actuators fastened via bolts. A singular layer whereby the dispensing assembly and chip assembly engage each other with the assistance of alignment members, using vertical fluid channels in communication with pillars as shown in U.S. Pat. No. 6,454,924 to Jedrzejewski, et al. The sealing of the mated ports and reservoirs (U.S. Pat. No. 6,251,343 to Dubrow et al.) of the body structure include adhesives, bonding materials (U.S. Pat. No. 5,882,465 to McReynolds); negative pressure (US Pat. Appln. Pub. 2003/0206832 by Thiebaud, et al.); rubber O-rings (US Pat. Appln. Pub. 2002/0093143 by Tai, et al.); ultrasound welding, thermal processes (US Pat. Appln. 2002/0023684 by Chow), and the like.
Microfluidic devices with and without sensor electrode layers have been used to measure bacterial growth as described in US Pat. Appln. Publication 2004/0197899 to Gomez et al., U.S. Pat. No. 6,716,620 to Bashir et al., U.S. Pat. Appln. Publication 2003/0023149 to Montemagno et al., US Pat. Appln. Publication 2002/0055167 to Pourahmadi et al. and U.S. Pat. No. 5,536,662 to Humphries et al. Microfluidic devices have also been designed to measure chlorine as discussed in U.S. Pat. No. 6,740,225 to Gurry et al. and U.S. Pat. No. 6,689,602 to Keeping et al. U.S. Pat. No. 6,524,790 to Kopf-Sill et al. is directed to a microfluidic system that uses enzymes and software to monitor fluid flow.
Microfluidic devices for measuring biochemical oxygen demand (BOD) are discussed in U.S. Pat. Appln. Publication 2002/0034818 to Schillig et al. with a membrane reactor in the flow channel and U.S. Pat. Appln. Publication 2002/0015992 to Keeping et al. uses a membrane trap. Miniaturized oxygen electrodes are used in a microfluidic device disclosed in U.S. Pat. No. 4,975,175 to Karube et al.
The above references confirm that microfluidic devices, systems and apparatus are available; however, the problems are that the available systems are custom-made with multiple parts, limited to specific applications, expensive and in need of major improvements. C. Gartner et al. discussed one needed improvement which includes standardizing the interfacing of microfluidic devices to the macroworld in “Polymer Based Microfluidic Devices—Examples for Fluidic Interfaces and Standardization Concepts” Proceedings of SPIE—The International Society for Optical Engineering, Vol. 4982, pages 99-104, Jan. 27-29, 2003. C. Gartner et al. provide microfluidic devices with multiple parts that attach to standard devices, such as syringes.
There is a need for a reliable, easy to manufacture, inexpensive packaging architecture to make viable fluidic and electrical connections to micro machined microfluidic devices. The present invention provides consumers with an inexpensive, disposable, easy to fabricate, interconnecting, one-piece, microfluidic package suitable for snap-in (interlocking) configurations and for combination with integrated sensor components on a single substrate that functions as a biosensor.